Electronic fence capable of guiding animals to return

ABSTRACT

An electronic fence system capable of guiding animals under training to return to a predetermined restricted area. The electronic fence generates electric shocks as the animals attempt to leave the predetermined restricted area and restrains the electrical shock when the animals return to the predetermined restricted area. The electronic fence includes a transmitter and a receiver. The transmitter transmits RF signals having a plurality of control signals such that different shock levels are generated responsive to the location of the animals within the predetermined restricted area. The receiver sets a shock wave level, selectively controls the generation of the electric shock and a high-frequency beep, automatically restrains the generation of the electric shock when an escaped animal returns to the predetermined restricted area, and generates an audible alarm and turns lamps on and off to indicate the location of the animal when it escapes from the predefined restricted area.

CROSS REFERENCE TO RELATED PATENTS

This application claims priority to Korean Patent Application Serial No.10-2004-0087608, filed Oct. 30, 2004, under 35 U.S.C. 119 which isincorporated herein by reference in its entirety for all purposes.

BACKGROUND OF THE INVENTION

1. Technical Field of the Invention

The present invention relates to an electronic fence, and moreparticularly, to an electronic fence capable of guiding animals undertraining to return to a predetermined restricted area.

2. Description of the Related Art

FIG. 1 shows a conventional electronic fence. In FIG. 1, transmitter 100is connected to a transmission wire antenna 110 for transmitting anelectric wave. Transmitter 100 includes an electric shock level control101 for setting the level of an electric shock to be applied to animals,an antenna checking lamp 102, a power switch 103, and a transmitterpower level control 104.

The operation of the conventional electronic fence will now beexplained. A user turns on the power switch 103 included in thetransmitter 100 and operates the shock level control 101 of thetransmitter 100 to set the level of the electric shock to be applied tothe animals. In addition, the user operates the transmitter power levelcontrol 104 to set a predetermined transmitter power level. Then, thetransmission wire antenna 110, included in the electronic fence toprevent the animals from escaping, is operated to generate a signal.

In this state, when an animal wearing a receiver approaches the fence, areceiving antenna receives the signal transmitted from the transmitter100 and a detector demodulates the received signal into the originalsignal. When the demodulated signal is an electric shock, the receivergenerates a electric shock, having the level corresponding to the levelof the transmitted signal, through a pair of electrodes. Accordingly,the animal cannot get out of the transmission wire antenna 110.

However, the aforementioned electronic fence generates an electric shockhaving a constant level when the animal escapes from a restricted area,and thus it is not efficient. Furthermore, the electric shock isgenerated when the escaped animal returns to the restricted area. Thus,the animal cannot enter the electronic fence due to the electric shockand the animal may run away.

When excited, some animals can run at speeds up to 100 Km/hour (62miles/hour). At these speeds, the animal can escape the restricted areabefore an electric shock is applied to them. Furthermore, when theanimals calm down and return home they typically return at a much slowerpace. The conventional electronic fence cannot detect the direction theanimals are moving relative to the restricted area and will generatedthe electronic shock as the animals attempt to enter the restrictedarea. If an electric shock is given to the animals when they arereturning to the restricted area, the animals are deterred from enteringthe conventional electronic fence and may run away and become lost orinjured in car accidents.

BRIEF SUMMARY OF THE INVENTION

Accordingly, the embodiment of the present invention has been made tosolve the above problems, and it is an object of the present inventionto provide an electronic fence capable of guiding animals under trainingto return to a predetermined restricted area, which automaticallycontrols an electric shock level in response to the animals' locationwithin the predetermined restricted area thereby efficiently controllingthe animals within the predetermined restricted area. The presentinvention determines the animal's direction of travel relative to aplurality of loop antennas defining an internal and external boundary ofthe electronic fence so as not to generate an electrical shock when anescaped animal returns to the predetermined restricted area.

To accomplish this, the embodiment of the present invention includes atransmitter, a receiver, and the plurality of loop antennas. Thetransmitter transmits a plurality of radio frequency (RF) signals overat least a first and a second loop antenna of the plurality of loopantennas such that a plurality of control stimuli are generated inresponse to the animal's position within the boundary of thepredetermined restricted area. The transmitter further generates aplurality of control signals for indicating a selected receiverfunction, including at least one of a vibration, a high-frequency beep,and a shock. In response to the received control signals, the receiversets an electric shock level and determines whether or not ahigh-frequency beep is generated, selectively controls the generation ofthe electric shock and high-frequency beep, automatically restrains thegeneration of the electric shock when an escaped animal returns to thepredetermined restricted area, and generates an audible alarm and turnsposition confirming lamps on and off to indicate the location of theanimal visually and aurally when an animal escapes from thepredetermined restricted area.

The transmitter includes: a power switch for providing power or blockingthe supply of power; an AC-DC converter for converting AC power suppliedthrough the power switch into DC power having a predetermined level; afunction select switch for selecting a desired receiver function; anelectric shock level control for setting the level of the electricshock; a transmitter power level control for controlling a transmitterpower level; a frequency output circuit for controlling the transmitterpower level under the control of the transmitter power level control; amicroprocessor for generating the plurality of control signals thatindicate the level set by the electric shock level control and thefunction selected by the function select switch; an antenna loopconfirming lamp, a beep selecting lamp, an electric shock selecting lampand an automatic selecting lamp for indicating the antenna loopoperating state, whether a high-frequency beep is selected, whether theelectric shock is selected and whether automatic selection is chosen,respectively, under the control of the microprocessor; a modulationcircuit for modulating the plurality of control signals generated by themicroprocessor into the RF signals; a loop detecting circuit connectedto the modulation circuit to detect a loop error and transmitting theloop error to the microprocessor; and a plurality of loop antennasincluding at least a first loop antenna and a second loop antenna forradiating the modulated RF signals into space.

The receiver includes: a power supply battery; a power controller forregulating the power supply battery output voltage and supplying theregulated output voltage to the receiver or, when the receiver is notused, automatically blocking the regulated output voltage from beingsupplied to the receiver; a belt for holding the receiver close to theanimal; a plurality of receiving antennas for receiving the RF signalstransmitted from one of the plurality of loop antennas of thetransmitter; an RF amplifier for amplifying the RF signals received bythe plurality of receiving antennas to a predetermined level; a detectorfor down-converting and demodulating the transmitted RF signals; amicroprocessor for selectively generating an electric shock levelsignal, controlling the power supplied to the receiver, generating asound driver control signal and a lamp driver control signal; a lampdriver for controlling the operations of the position confirming lampsand the operating lamp in response to the lamp driver control signaloutput from the microprocessor; an amplifier for amplifying the electricshock level signal operably coupled from the microprocessor to apredetermined level; a high-voltage transformer for producing a highvoltage and coupling the high voltage to a plurality of electric shockoutput terminals to output an electric shock; and a sound driver forcontrolling the operations of a buzzer and a horn according to the sounddriver control signal output from the microprocessor.

The above-referenced description of the summary of the inventioncaptures some, but not all, of the various aspects of the presentinvention. The claims are directed to some of the various otherembodiments of the subject matter towards which the present invention isdirected. In addition, other aspects, advantages, and novel features ofthe invention will become apparent from the following detaileddescription of the invention when considered in conjunction with theaccompanying drawings.

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS

The above and other objects, features, and advantages of the presentinvention will be apparent from the following detailed description ofthe preferred embodiments of the invention in conjunction with theaccompanying drawings, in which:

FIG. 1 illustrates a conventional electronic fence;

FIG. 2 illustrates a transmitter of the electronic fence according tothe present invention;

FIGS. 3A and 3B illustrate a receiver of the electronic fence accordingto the present invention;

FIG. 4 is a schematic block diagram of the transmitter of the electronicfence according to the present invention; and

FIG. 5 is a schematic block diagram of the receiver of the electronicfence according to the present invention.

DETAILED DESCRIPTION OF THE INVENTION

Reference will now be made to the preferred embodiments of the presentinvention, examples of which are illustrated in the accompanyingdrawings.

FIG. 2 illustrates a transmitter 1 of an electronic fence according tothe present invention. Transmitter 1 transmits RF signals having aplurality of control signals such that a plurality of control stimuliare generated in response to the position of an animal moving close tothe boundary of a predetermined restricted area. In addition,transmitter 1 generates a plurality of control signals for indicating aselected function.

The electronic fence of the present invention includes a power switch 2,a transmitter power level control 3, an electric shock level control 4for selecting a shock level over a range from zero to full scale, afunction select switch 5, an antenna loop confirming lamp 6, a beepselecting lamp 7, an electric shock selecting lamp 8, an automaticselecting lamp 9, and first and second loop antennas 11 and 13,respectively.

Power switch 2 provides power to the transmitter. The transmitter powerlevel control 3 controls a transmitter power level. The electric shocklevel control 4 sets the level of the electric shock. The functionselect switch 5 is used to select a desired function: vibration,high-frequency beep, vibration with high-frequency beep, and shock. Theantenna loop confirming lamp 6 illuminates to indicate that one of theantenna loops has an error, and a beep selecting lamp 7 indicateswhether a high-frequency beep is selected or not. The electric shockselecting lamp 8 and automatic selecting lamp 9 indicate whether theelectric shock is selected and whether automatic selection is chosen,respectively.

FIG. 3A illustrates receiver 21 of the electronic fence according to thepresent invention. Receiver 21 includes a belt 22 to connect receiver 21to the animal, a plurality of electric shock output terminals 23, abuzzer 24 (internal to receiver 21 thus not shown), a horn 25, positionconfirming lamps 26, and an operating lamp 27. The receiver 21, inresponse to the RF signals transmitted from the transmitter (transmitter1 of FIG. 2), selectively controls the generation of the electric shock,vibration, and high-frequency beep. In addition, receiver 21automatically restrains the generation of the electric shock when anescaped animal returns to the predetermined restricted area and, when ananimal escapes from the predetermined restricted area, generates theaudible alarm and turns the position confirming lamps on and off toindicate the location of the animal both visually and aurally. FIG. 3Billustrates a side view of receiver 21 and of collar 22. Specifically,FIG. 3B illustrates one embodiment of the invention with a set oforthogonal receiving antennas 28. As may also be seen, orthogonalantennas 28, in one embodiment, are operable to rotate as a unit about apivot point where the antennas couple to the collar 22 of receiver 21.In operation, the orthogonal antennas are rotated about the pivot pointto facilitate the receiver 21 determining relative location of theanimal with respect to at least two radiating loops of the electronicfence to facilitate the ability of logic to determine whether a dog isentering or exiting the areas defined by the loop(s) of the electronicfence or, more generally, the location of the animal for all purposesdescribed herein.

FIG. 4 is a schematic block diagram of the transmitter of the electronicfence according to the present invention. Transmitter 1 includes a powerswitch 2, a transmitter power level control 3, a electric shock levelcontrol 4, a function select switch 5, an antenna loop confirming lamp6, a beep selecting lamp 7, an electric shock selecting lamp 8, anautomatic selecting lamp 9, an AC-DC converter 10, a first loop antenna11, a second loop antenna 13, a modulation circuit 14, a loop detectingcircuit 15, a microprocessor 16, and a frequency output circuit 17.

When power switch 2 is turned on, AC-DC converter 10 converts input ACpower into DC power at a predetermined level and supplies the DC powerto the transmitter.

When the microprocessor 16 is provided with DC power, it initializes thecircuits of transmitter 1 and then places the transmitter into atransmit state in which the transmitter transmits a plurality of RFsignals to the receiver (receiver 21 of FIG. 3). In this transmit state,when a user operates electric shock level control 4 for setting theelectric shock level, a corresponding electric shock level controlsignal is sent to a central processing unit (CPU) 16 d of microprocessor16 through an input controller 16 c. Subsequently, when the useroperates function select switch 5 to select one of vibration only,high-frequency beep only, vibration and high-frequency beep, or shock, acorresponding function select control signal is sent to CPU 16 d ofmicroprocessor 16 through input controller 16 c and a function lamp,(i.e., beep selecting lamp 7, electric shock selecting lamp 8, andautomatic selecting lamp 9) is turned on in response to the selectedfunction so that the user can easily recognize the selected function.

CPU 16 d of microprocessor 16 stores the plurality of control signalsuntil it determines that function selection is complete. At this time,CPU 16 d operably couples the plurality of control signals to encoder 16a. The encoder arranges the plurality of control signals into serialdata signal suitable for transmission having a start signal, an addresssignal, function key data, electric shock level data, and a stop signal.Encoder 16 a operably couples the serial data signal to modulationcircuit 14 when microprocessor 16 determines that the user's operationis completed. Stated differently, microprocessor 16 encodes theplurality of control signals into the serial data signal when the userhas completed adjustment of one of the function select switch, theelectric shock level control, and the transmitter power level control.

Modulation circuit 14 modulates the serial data signal into RF signalsusing a local oscillation frequency, as is known to one of average skillin the art. The RF signals are radiated into space through the firstloop antenna 11 and second loop antenna 13. The loop detecting circuit15 is operably coupled to modulation circuit 14 and detects when theloop antenna is not working properly or not connected. When an error isdetected, loop detecting circuit 15 sends a signal microprocessor 16 inorder to halt transmitter operation. Microprocessor 16 responds byturning on antenna loop confirming lamp 6.

FIG. 5 is a schematic block diagram of the receiver of the electronicfence according to the present invention. Receiver 21 includes a powersupply battery 36, a power controller 37, a plurality of receivingantennas 28, a RF amplifier 29, a detector 30, a microprocessor 31, alamp driver 32, an amplifier 33, a high-voltage transformer 34, and asound driver 35. Microprocessor 31 includes an input port 31 a, a lightcontroller 31 b, a level controller 31 c, a sound controller 31 d, and acentral processing unit (CPU) 31 e.

The power controller 37 regulates the output voltage of the power supplybattery 36 and supplies the regulated voltage to the receiver. When thereceiver is not used for a period of time, power controller 37automatically limits the power supplied to the receiver to conservepower. The plurality of receiving antennas 28 receives the RF signalstransmitted from the transmitter (transmitter 1 of FIG. 2). At least twoof the plurality of receiving antennas 28 are positioned at right angles(90 degrees) to each other. This allows receiver 21 to determine theanimals approach to the electronic fence from any direction, i.e.,increases the receiver sensitivity to the first and second loop antennasof the transmitter (transmitter 1 of FIG. 2). RF amplifier 29, operablycoupled to receive the RF signals from the plurality of receivingantennas 28, amplifies the RF signals to a predetermined level. Theamplified RF signals are operably coupled to detector 30 thatdown-converts and demodulates the RF signals into the original serialdata signal, as is known by one of average skill in the art. Detector 30operably couples the demodulated serial data signal to input port 31 aof microprocessor 31. Input port 31 a decodes the demodulated serialdata signal into the original start signal, address signal, function keydata, shock wave level data, and stop signal and produces the functionkey data and shock wave level data to CPU 31 e for processing.

CPU 31 e, in response to the shock wave level control data, selectivelygenerates a parallel bit word to level controller 31 c that converts theparallel bit word into the electric shock level signal that is producedto amplifier 33. Amplifier 33 amplifies the electric shock level signalto the predetermined level. The high-voltage transformer 34 boosts theamplified electric shock level signal coupled from amplifier 33 to thehigh voltage and couples the high voltage to the plurality of electricshock output terminals 23 to produce the electric shock.

CPU 31 e of microprocessor 31 selectively controls the power supplied tothe receiver by power controller 37, generates the sound driver controlsignal, and the lamp driver control signal in response to the functionkey data operably coupled from input port 31 a. Lamp driver 32 controlsthe operation of a position confirming lamp 26 that turns on and offwhen the animal escapes and an operating lamp 27 that indicates thereceiver is operating normally. Sound driver 35 controls the operationsof a buzzer 24 and a horn 25 according to the sound driver controlsignal operably coupled from microprocessor 31 via sound controller 31d. Buzzer 24 produces a vibration that is used as a warning signal tocontrol the animal when it approaches the first loop antenna. Thevibration may be used alone or may be used in conjunction with theelectric shock and high-frequency beep to control the animal.

When the RF signals radiated through the transmitter first and secondloop antennas (first loop antenna 11 and second loop antenna 13 of FIG.2) are received by the plurality of receiving antennas 28, the functionkey data are received and processed by receiver 21 that generates one ofthe lamp driver control signal, the electric shock level signal, and thesound driver control signal when an animal wearing receiver 21approaches the first or second loop antenna (first loop antenna 11 andsecond loop antenna 13 of FIG. 2).

In the operation of the electronic fence, microprocessor 31 of receiver21 receives the output signal of detector 30 to determine whether thereceiver has received a signal from the transmitter. Here, the operationof receiver 21 depends on whether the received signal is the outputsignal of the first loop antenna 11 or the output signal of the secondloop antenna 13. For example, when receiver 21 receives the outputsignal of the first loop antenna 11 first, the receiver judges that ananimal is approaching the boundary of the predetermined restricted areain an attempt to get out of the area and operates only the sound driver35 to generate at least one of the vibration warning through buzzer 24and the high-frequency beep through the horn 25, depending on thefunction key data received from the transmitter.

When the animal approaches the boundary of the predetermined restrictedarea while the vibration is being generated, the microprocessor 31generates a signal to controller 31C that generates the electric shocklevel signal sufficient for a low level electric shock. The electricshock level signal is amplified by the amplifier 33 to the predeterminedlevel and then operably coupled to high-voltage transformer 34.High-voltage transformer 34 boosts the amplified signal to a highvoltage and applies the high voltage to the plurality of electric shockoutput terminals 23 such that the low level (i.e., weak) electric shockis generated to stimulate the neck of the animal. Accordingly, as longas the animal does not continue to move forward toward the predeterminedrestricted area then the generated electric shock is weak.

If the animal continues to move forward toward the predeterminedrestricted area even when the weak electric shock is being generated,the receiver will receive a signal from the second loop antenna 13. Inthis condition, the microprocessor 31 generates the electric shock levelsignal for a high level shock based on the setting of the transmitterelectric shock level control. Level controller 31 c generates a highlevel electric shock level signal that is amplified by amplifier 33 tothe predetermined level and then operably coupled to high-voltagetransformer 34. High-voltage transformer 34 boosts the amplified signalto a high voltage suitable to generate the high level shock and appliesthe high voltage to the plurality of electric shock output terminals 23such that a high level electric shock is generated to stimulate the neckof the animal. Accordingly, the animal is stimulated to move away fromthe second loop antenna and thus remain within the predeterminedrestricted area. In one embodiment of the invention, the first (inner)loop antenna is positioned a specific distance of approximately twoyards from the second (outer) loop antenna. Further, the full scalelevel of electric shock is 1500 volts in one embodiment of the inventionbased upon transmissions from the second loop antenna.

When receiver 21 receives the signal of the second loop antenna (secondloop antenna 13 of FIG. 2) and then receives the signal of the firstloop antenna (first loop antenna 11 of FIG. 2), the receiver determinesthat the escaped animal is attempting to return to the predeterminedrestricted area so receiver 21 restrains the generation of the electricshock and the audible alarm. When the receiver no longer receives thesignal of the first loop antenna, the receiver determines that theanimal has returned to the predetermined restricted area, stops thegeneration of the electric shock and the audible alarm signal, andreturns to its initial state.

However, when the receiver no longer receives the signal of the secondloop antenna after first receiving the signal of the second loop antennaand the animal is receiving the strongest electric shock, the receiver21 judges that the animal has escaped from the predetermined restrictedarea and operates horn 25 through the sound driver 35 to generate a loudsound so that the user can aurally confirm the location of the animal.Additionally, when microprocessor 31 determines that the animal hasescaped, it sequentially illuminates position confirming lamps 26 toassist the owner in locating the animal.

When the escaped animal returns to the predetermined restricted area andthe receiver again receives the signal of the second loop antenna, thereceiver restrains the generation of the electric shock and the alarmsignal such that the animal can return to a position within thepredetermined restricted area.

Additionally, microprocessor 31 checks an inactivity timer using aninternally stored program. Specifically, the microprocessor 31 startscounting time from the moment the receiver is last used. When thecounted time exceeds a predetermined period of time (5 hours, forexample), microprocessor 31 automatically generates a power controllersignal to power controller 37. Power controller 37 reduces the outputvoltage to receiver 21 to reduce power consumption.

The embodiment of the present invention includes a luminous reflectionbelt (belt 22 of FIG. 3) in order to make the escaped animal morevisible at night. This reflective belt is helpful in locating theanimal. For example, if the battery is out of charge resulting in theaudible alarm and position confirming lamps becoming substantiallyinoperable, the reflective collar facilitates the animal being seen atnight from a distance.

As described above, the electronic fence of the present invention setsan electric shock level in response to the position of an animal movingclose to the boundary of a predetermined restricted area. Thus, theanimal can be restrained from escaping from the predetermined restrictedarea without giving an excessive electric shock to the animal.Furthermore, the present invention can generate an extremely loud soundand bright lights through receiver 21 connected to belt 22 the animalwears so that the location of the animal can be easily detected when theanimal gets out of the predetermined restricted area. Moreover, thepresent invention can restrain the generation of electric shock when theescaped animal returns to the predetermined restricted animal and thusthe animal can come back safely.

The invention disclosed herein is susceptible to various modificationsand alternative forms. Specific embodiments therefore have been shown byway of example in the drawings and detailed description. It should beunderstood, however, that the drawings and detailed description theretoare not intended to limit the invention to the particular formdisclosed, but on the contrary, the invention is to cover allmodifications, equivalents, and alternatives falling within the spiritand scope of the present invention as defined by the claims.

1. An electronic fence system capable of guiding animals to return,comprising: a transmitter for generating radio frequency (RF) signals; aplurality of loop antennas, defining a boundary of a predeterminedrestricted area, for radiating the RF signals into space wherein theplurality of loop antennas includes at least a first loop antenna and asecond loop antenna defining an internal and external boundary,respectively, of the predetermined restricted area and further whereinthe first loop antenna is positioned a specified distance inside thesecond loop antenna; wherein the transmitter is operable to selectbetween a plurality of functions and to generate a control commandspecifying at least one of vibration, high-frequency beep, vibrationwith high frequency beep, shock and shock intensity wherein thetransmitter includes: a power switch for selectively providing andblocking power to the transmitter; an AC-DC converter for converting ACpower supplied through the power switch into DC power having apredetermined level; a function select switch for selecting a desiredreceiver function; an electric shock level control for setting a levelof an electric shock; a transmitter power level control for controllinga transmitter power level; a frequency output circuit for controllingsaid transmitter power level under the control of the transmitter powerlevel control; a transmitter microprocessor for generating a pluralityof control signals defining the operational state of a receiver; anantenna loop confirming lamp for indicating an antenna loop operatingstate; a beep selecting lamp for indicating a high-frequency beep isselected; an electric shock selecting lamp for indicating the electricshock is selected; an automatic selecting lamp for indicating automaticoperation is selected; an encoder for converting the plurality ofcontrol signals received from the microprocessor into a serial datasignal suitable for transmission; a modulation circuit for modulatingthe serial data signal produced by the encoder into the RF signals; anda loop detecting circuit operably coupled to the modulation circuit todetect a transmission loop error and for transmitting the transmissionloop error to the microprocessor; and wherein the receiver receives thetransmitted RF signals and the control command and initiates astimulation based upon the control command, the receiver furtherincluding a plurality of antennas structurally arranged to define aninety degree axial orientation relative to each other wherein thereceiver is operable to determine the animal's approach to an electronicfence from any direction.
 2. The electronic fence system of claim 1,wherein the specified distance is approximately two yards.
 3. Theelectronic fence system of claim 1, wherein the electric shock levelcontrol sets the level of the electric shock from zero to full scale. 4.The electronic fence system of claim 3, wherein the full scale level ofthe electric shock is 1500 volts.
 5. The electronic fence system ofclaim 1, wherein the receiver comprises: a belt for holding the receiverin close proximity to the animal; wherein the plurality of receivingantennas for receiving the RF signals transmitted from the transmitterare attached to the belt; a plurality of electric shock outputterminals; a horn for sounding a high-frequency beep and an audiblealarm; a buzzer for generating a vibration; and receiver circuitry forprocessing the transmitted RF signals operably coupled from theplurality of receiving antennas, wherein the receiver circuitry isoperably disposed to prompt the horn to sound, the buzzer to generatethe vibration, the electric shock terminals to generate the electricshock based upon logic determining that a location of the animalrequires one or more of these stimulations.
 6. The electronic fencesystem of claim 5 wherein the belt includes a visible reflectivesurface.
 7. The electronic fence system of claim 5, wherein thereceiving circuitry includes: a power supply battery; a power controllerfor regulating an output voltage of the power supply battery and forautomatically controlling the regulated output voltage to the receiversuch that the regulated output voltage is reduced after a period ofinactivity; an RF amplifier for amplifying the RF signal received by thereceiving antenna to a predetermined level; a detector fordown-converting and demodulating the RF signal coupled from the RFamplifier into the serial data signal; a receiver microprocessor forselectively generating a plurality of function control signals, theplurality of function control signals including: an electric shock levelsignal; a lamp driver control signal; a sound driver control signal; alamp driver for controlling operation of a plurality of lamps; anamplifier for amplifying the electric shock level signal to apredetermined level; a high-voltage transformer for boosting theamplified electric shock level signal to a high voltage; and a sounddriver for controlling the operations of the buzzer and the hornaccording to the sound driver control signal.
 8. The electronic fencesystem of claim 7, wherein the receiver circuitry is operable to: setthe electric shock level; determine whether or not to generate ahigh-frequency beep in response to the RF signals transmitted from thetransmitter; selectively control the generation of the electric shock;and the level of the electric shock in response to the animal movingclose to at least one of the first loop antenna and second loop antennadefining the internal and external boundary of the predeterminedrestricted area; generate auditory and visual signals to indicate thelocation of the animal when the animal escapes from the predeterminedrestricted area; and restrain the generation of the electric shock whenthe escaped animal returns to the predetermined restricted area.
 9. Theelectronic fence system of claim 8, wherein the receiver microprocessor:causes the sound driver to generate only a high-frequency beep when thereceiver receives the RF signal transmitted from the transmitter firstloop antenna; causes the high-frequency beep and a low level electricshock to be generated when the receiver continuously receives the RFsignal transmitted from the transmitter first loop antenna; causes ahigh level electric shock to be generated when the receiver receives theRF signal transmitted from the transmitter first loop antenna and thenreceives the RF signal transmitted from the transmitter second loopantenna; and generates an audible alarm and, simultaneously, turnsposition confirming lamps on and off based upon whether the receiverreceives the RF signal transmitted from the transmitter second loopantenna.
 10. The electronic fence system of claim 9 wherein the receivermicroprocessor is operable to determine that an escaped animal hasreturned to the predetermined restricted area and restrains thegeneration of the electric shock when the receiver receives the RFsignal transmitted from the transmitter second loop antenna afterreceiving the RF signal transmitted from the transmitter second loopantenna and then receiving no other RF signals, or when the receiverreceives the RF signal transmitted from the transmitter first loopantenna after receiving the RF signal transmitted from the transmittersecond loop antenna.
 11. An electronic fence system capable of guidinganimals to return, comprising: a transmitter for generating radiofrequency (RF) signals wherein the transmitter includes: a power switchfor selectively providing and blocking power to the transmitter; anAC-DC converter for converting AC power supplied through the powerswitch into DC power having a predetermined level; a function selectswitch for selecting a desired receiver function; an electric shocklevel control for setting a level of an electric shock; a transmitterpower level control for controlling a transmitter power level; afrequency output circuit for controlling said transmitter power levelunder the control of the transmitter power level control; a transmittermicroprocessor for generating a plurality of control signals definingthe operational state of a receiver a beep selecting lamp for indicatinga high-frequency beep is selected; an electric shock selecting lamp forindicating the electric shock is selected; and an automatic selectinglamp for indicating automatic operation is selected; an encoder forconverting the plurality of control signals received from themicroprocessor into a serial data signal suitable for transmission; anda modulation circuit and transmission circuit for modulating andtransmitting the serial data signal produced by the encoder into the RFsignals; a plurality of loop antennas operably coupled to thetransmitter, the plurality of loop antennas defining a boundary of apredetermined restricted area, for radiating the RF signals into spacewherein the plurality of loop antennas includes at least a first loopantenna and a second loop antenna defining an internal and externalboundary, respectively, of the predetermined restricted area and furtherwherein the first loop antenna is positioned a specified distance insidethe second loop antenna; wherein the receiver receives the transmittedRF signals and the control command and initiates a stimulation basedupon the control command, the receiver further including a plurality oforthogonal antennas structurally arranged to define a ninety degreeaxial orientation relative to each other wherein the receiver isoperable to determine the animal's approach to an electronic fence fromany direction; and wherein the receiver is operable to trigger differentlevels of stimulation based upon location of the receiver in relation tothe first and second loops and based upon signals received from at leastone of the first and second loops through at least one of the pluralityof orthogonal antennas.
 12. The electronic fence system of claim 11wherein the transmitter is operable to select between a plurality offunctions and to generate a control command specifying at least one ofvibration, high-frequency beep, vibration with high frequency beep,shock and shock intensity.
 13. The electronic fence system of claim 11wherein the different levels of stimulation include different types ofstimulation.
 14. The electronic fence system of claim 11 wherein thedifferent levels of stimulation include different levels of electricalshock for a constant shock level setting of the transmitter.
 15. Theelectronic fence system of claim 14 wherein the electric shock levelcontrol sets the level of the electric shock from zero to full scale.16. The electronic fence system of claim 14 wherein the full scale levelof the electric shock is 1500 volts.
 17. The electronic fence system ofclaim 11 wherein the specified distance is approximately two yards.